Although enameled products such as enameled panel, enameled blackboard and enameled chimney have a relatively low degree of forming, these enameled products have so far been produced, in a process as shown in FIG. 2a, in the same way as in enameled products having a higher degree of forming, using an enameling cold rolled steel sheet produced in the process shown in FIG. 1a. More specifically, in the production process of enameling cold rolled steel sheet, as shown in FIG. 1a, a hot rolled steel sheet is sequentially subjected to treatments such as pickling, cold rolling, electrolytic cleaning, annealing and skin pass rolling. Next, in the production process of enameled products, as shown in FIG. 2a, said enameling cold rolled steel sheet produced in the above mentioned process is subjected to treatments such as forming, degreasing, pickling, Ni-dipping, neutralization, drying, enameling and baking for producing the abovementioned enameled products.
However, the production method of the enameled products mentioned above not only requires subtantial cost because it comprises a plurality of production processes, but also fails to decrease enameling defects for such time and labor required. Besides, since acids are used in large quantities, the method has a disadvantage in that there is a possibility of causing environmental problems in relation to the disposal of waste acids after use.
For example, an unbaked enameling steel sheet (Japanese Patent Publication No. 29,289/73) has been proposed as a method that solves these problems. However, this method requires the steel sheet manufacturer to install facilities for enameling and drying. Further, it is expensive also in that a resin, which is unnecessary for the enameled products after baking, is used. Besides, it has a disadvantage in that said resin will be cracked on baking to generate black smoke, thus causing air pollution.